Sewing machine



y 6, 1- A. L. WILMOTH 2,241,230

SEWING MACHINE Filed July '7, 1957 4 Sheets-Sheet l W1 TNESSES:INVENTOR:

firihurL- mlmoih y 6; 1941- A. L. WILMOTH 2,241,230

SEWING MACHINE Filed July '7, 1957 4 SheetsSheet 2 I'V1 'IINESSES; I NVENTOR firihur L- Wilmoih,

A TTORN E YS y 1941- A. 1.. WILMOTH 2,241,230

SEWING MACHINE Filed July '7, 1957 4 Sheets-Sheet 3 WITNESSES INVENTOR:

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May 6, 1941. L. WILMVOTH SEWING MACHINE I 4 Sheets-Sheet 4 Filed July'7, 1957 FIG; QET

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I By TTORNEYS.

Patented May 6, 1941 snwmc MACHINE Arthur L. Wilmoth, San Francisco,Calif., assignor to Union Special Machine Company, Chicago, 11]., acorporation of Illinois 1 Application July 7, 1937, Serial No. 152,381

This invention relates to sewing machines; and it has reference moreparticularly to sewing machines intended for operation upon pile fabricssuch, for example, as velours and the like, used in the upholstering ofautomobiles. Such material is ordinarily coated at the back with latexfor anchorage of the pile, and in being seamed in a sewing machine,layers thereof are superimposed one upon another with their pile facesfacing each other so that when'the united layers are subsequentlyturnedoutward, the. stitches of the seams are entirely concealed.Considerable difliculty has been experienced with feeding oflatex-backed fabrics, placed as pointed out, in an ordinary sewingmachine due to retardation of the upper layer by friction between thetacky latex backing of the latter and the presser foot of the machine.Attempts were made heretofore to overcome this diiiiculty with the aidof a freely supported non-driven endless belt guided to pass beneath thepresser foot and thereby prevent direct contact of the latter with theback of the upper layer of the material, but this expedient has provedto be only partially satisfactory.

The chief aim of my invention is to provide for the positive feeding ofthe uppermost layer of the material concurrently with advance of thelowermost layer by the usual feeding instrumentality of the sewingmachine. This desideratum I attain as hereinafter more fully explainedthrough provision of-a slip drive means whereby a belt such as abovereferred to is caused to advance the upper layer of the material duringthe active periods of the feeding element of the sewing machine butpermitted to be held quiescent by friction with the backing of theuppermost layer during the inactive periods of said feeding element.

Other objects and attendant advantages will appear from. the followingdetailed description of the attached drawings wherein Fig. I is alongitudinal elevation of a sewing machine embodying my invention.

Fig. II shows the front or head end of the machine in elevation.

Fig. III is a detail cross section on a larger scale taken as indicatedby the arrows III-III in Fig. I.

Fig. IV is a fragmentary detail view in plan similarly on a larger scalelooking as indicated by the arrows IVIV in Fig. II.

Fig. V is a detail sectional view taken as indicated by the arrows VV inFig. I; and

Fig. VI is a fragmentary detail view looking as indicated by the arrowsVI-VI in Fig. V.

The machine'chosen for convenience of illustrating my invention has ahorizontal plate like work support I suitably sustained at an elevationabove the base 2 of the machine frame. Extending forwardly from anintegral standard or upright I at one end of the base 2 is an am 4 whichover-reaches the work support I and which, as usual, terminates in ahead 5 wherein a needle bar 6 carrying the needle 1, and the presser barI carrying the presser foot 9 of the sewing machine are guided forvertical movement. Journaled in suitable bearings beneath the worksupport is the longitudinally extending main or drive shaft ill of themachine which is fitted at one end with -a combined hand and belt wheelI I, and from which, through interposed connections (not shown) withinthe hollows of the frame, the needle bar 6 is actuated in a 'well knownmanner. The illustrated machine also has a four-motion feed dog I 2arranged directly beneath the presser foot 9 to engage the back of thelower layer L (Figs. V and VI) of the pile material which is to besewed, from beneathand to intermittently advance it on the work supportI relative to the needle I. As usual,

the feed dog I 2 is mounted on a carrier bar l3 which receives its backand forth or feeding movements and its up and down or lifting movementsfrom the main shaft of the machine, through the mechanismcomprehensively desig nated by the numeral l4 in Figs. I and II.

For the purpose of assisting the feeding of the material in a machine ofthe kind briefly described up to this point, I have provided auxiliarymeans as follows:

Trained for travel around the needle head 5 is a relatively thickendless belt l5 preferably in the form of a tape closely woven from hardtwisted textile yarn, as conventionally shown in Figs. V and VI,,saidbelt being confined to travel in a predetermined path by a series ofspool-like idler pulleys I6, I! and I8 supported with capacity for freerotation individually by a T-shaped bracket l9 secured to the top ofsaid needle head by a screw bolt 20, see Figs I and II. From Fig. II, itwill be observed that the belt l5 passes under the presser foot 9whereof the ends are rounded as at 2| and 22 and the bottom surfacelongitudinally recessed or grooved as at 23 to facilitate movement ofthe belt and to guide it. From Figs. I, V, and VI, it will be furtherobserved that the depth of the groove 23 in the presser foot 9 is lessthan the thickness of the For the purpose of driving the belt, Ihavepro'- vided means including a pair of opposingcircumferentially-corrugated nip rolls 25, 26 which are disposed at anelevation above the work support I and which engage said beltrespectively at I opposite sides. As shown in Fig. I, the shaft 21 ofthe nip roll 25 is substantially co-extensive in length' with theover-reaching arm 4 of the machine frame and journaled at its ends inbearings afflxed to one side of said arm. The shaft 28 of the other niproll 26, on the other hand, is journaled in a bearing 29 at the free endof an arm 30 which is pivoted at 3| on a bracket 32 secured to thecorresponding side of the head 5 by a pair of screws 33. A helicaltension spring 34 whereof one end-is engaged with a fixed anchorage 35on the bracket 32 and the other end with a screw 36 on the arm 30,serves to keep the nip roll 26 yieldingly in engagement with the belt i5so that the latter is pinched between the corrugated peripheries of saidroll and the companion nip roll 25. This arrangement permits the roll 26to be moved away from the belt l5 by moving the arm 30 outward about itspivotal connection 3| with the bracket 32 in which position said arm islocked. through engagement of a stud projection 31 thereon with a notch38 in the side of a latch lever 39 fulcrumed for pivotal movement aboutascrew 46 on the bracket 32, see Figs. 11 and IV. A coiled tension spring4| (Fig. IV) to which the latch lever 39 is subject, tends to yieldinglymaintain the notch 38 of said lever 39 engaged with the stud 31 on theroll carrying arm 30. By slight lateral pressure on the latch lever 39against the pull of the spring 4|, the arm is released and drawn inwardby the spring 34 to return the nip 'roll 26 to its normal position inengagement with the belt l5.

Secured to the shaft 21 of the nip roll 25 adjacent the bearing bracket42 is a pulley 43 of small diameter with a circumferential V-groove; andextending between said pulley and a similar pulley 44 of the same sizeat one end of a counter shaft 45 at a level below the work support I, isa tensioned coil spring belt 46, said counter shaft being journaled in abracket 41 secured by screws 49 to the base 2 at the side of the machineframe, Aflixed to the other end of the counter shaft 45 is a V-groovepulley 49 much larger than the pulleys 43, 44 and which is connected byanother tensioned coil spring belt 50 with a somewhat smaller V-groovepulley 5| on the drive shaft ID of the machine (see Figs. I and I11),the latter pulley being split for convenience of ready mounting on saiddrive shaft.

In practice, the belt I5 is maintained under light tension so as toslide freely within the groove 23 of the presser foot 9, its tensionbeing regulatable by adjusting the stud axis 52 for the idler pulley I!(see Fig. II) up or down in a vertical slot shown at 53 in the T-bracket9. When necessary, due to stretch and accumulation of slack in the belt,the stud axes 54 and 55 of the idler pulleys l6 and I8 may betransferred respectively to other holes 56 and 51 provided for them inthe T-bracket |9 in a manner readily understandable from Fig. II.

' During the operation of the machine, as the feed dog |2 moves forwardon its active or feedin'g stroke in the direction of the arrow in Fig.11 to advance the lower layer L of the pile material on the work supportI, the belt |5 concurrently advances the upper layer L of said material,said belt slipping easily on the smooth hard under surface of thepresser foot 9 since it is under very light tension as above explained.During the retractive strokes of the feed dog l2, and while the needleis in the fabric, however, the belt I5 is held quiescent throughfriction with the rubberized backing of the upper layer L' of thematerial thereby reacting upon the nip rolls 25, 26 and temporarilypreventing their rotatiomthis being permitted through ability of thespring belt 46 to slip in the grooves of the pulleys 43, 44 which, aspreviously pointed out are of a small diameter much less than that ofthe pulleys 49 and 5| for the spring belt. It is to be noted, however,that even though held quiescent during the idle periods of the feed dog,

the belt is maintained under constant driving tension.

By. properly proportioning of the pulleys 43, 44, the auxiliary feedingmeans of my invention can be adapted to function as explained for anydesired stitch length to which the sewing machine is adjusted. Moreover,by reason of the fact that the portion of the belt IS in the intrvalbetween the rear end 22 of the presser foot 9 and the nip rolls 25, 26is maintained under a constant predetermined tension, any slackarisingthrough movement of the presser foot incident to passage thereunder ofcross seams or the like in the material, will be instantly taken up.

Having thus described my invention, I claim:

1. A sewing machine comprising a work support; a needle operated fromabove the work support; feeding means for engaging the fabric frombeneath and intermittently advancing it on the work support relative tothe needle; a presser foot operative to hold the material down on thework support; and auxiliary feeding means including an endless beltwhich runs under the presser foot and engages the material' from above,a pair of opposing nip rolls respectively engaging the belt fromopposite sides, a rotary shaft, and a slip belt of coiled spring wireconnecting a circumferentially-grooved pulley on the drive shaft with asimilar pulley on the shaft of one of the nip rolls.

"2. A sewing machine comprising a work support; a drive shaft journaledbeneath said work support; a needle operated from above the worksupport; feeding means for engaging the material being sewed frombeneath and advancing it on the work support relative to the needle; apresser foot operative to hold the material down on the work support;and auxiliary feeding means including an endless belt which runs underthe presser foot and engages the material from above, a pair of niprolls respectively engaging the belt from opposite sides, a rotarycounter shaft Journaled beneath the work support and driven .from thedrive shaft aforesaid, and a spring wire coii slip belt connecting a'circumferentially-grooved pulley on the counter shaft with a similarpulley on the shaft of one of the nip rolls.

3. A sewing machine comprising a work support; a drive shaft Journaledbeneath said work support; a needle operated from above the worksupport; feeding means for engaging the material being sewed frombeneath and advancing it on the work support relative to the needle; apresser foot operative to hold the material down on the work support;and auxiliary feeding means including an endless belt which runs underthe presser foot and engages the material from above, a pair of niprolls respectively the belt from opposite sides, a rotary counter shaftjournaled beneath the work support, a drive belt connecting a pulley onthe counter shaft with a pulley on the drive shaft aforesaid, and aspring wire slip belt connecting a circrunferentiallygrooved pulley ofsmaller diameter on the colmter shaft with a similar pulley on the shaftof one of the nip rolls.

4. A sewing machine comprising a work support with an over-reaching arm;a drive shaft journaled beneath the work support; a needle bar with aneedle guided for vertical reciprocation in a head at the free end ofthe over-reachingarm; feedingmeansfor thematerial being sewed frombeneath and it along said work support relative to the needle; a presserfoot operative to hold the material down on the work support; andauxiliary feeding means including an endless belt which runs under thepresser foot and engages the material from above, means defining acircuit for the belt around the head of the over-reaching arm; a pair ofnip rolls at an elevation above the work support respectively the beltfrom opposite sides; shafts respectively for said nip rolls journaled inbearings on the overarm of the machine frame, a counter shaft journaledat a level beneath that of the work support in parallel relation to thedrive shaft aforesaid, a horizontally-arranged belt connecting a pulleyon the counter shaft with a pulley on the drive shaft aforesaid, and avertically-arranged wire coil slip belt connecting acircmnferentiallygrooved pulley of smaller diameter on the counter shaftwith a similar pulley on the shaft of one of the nip rolls,

5. A sewing machine for uniting, while arranged face to face, two layersof pile fabric or the like having a frictional backing, comprising awork support; a reciprocating needle; intermittent feeding meansoperative at the stitch point for engaging the back of one layer of thematerial to intermittently shift it on the work support relative to theneedle; auxiliary feeding means including an element with a continuousrough-surface for eng n the back of the second fabric'layer opposite theintermittent feeding means at the stitch point; and slip drive means foractuating the auxiliary feeding element to effect synchronous advance ofthe second layer with the first during the active periods of theintermittent feeding means, but allowing said auxiliary feeding means toremain quiescent in contact with said second layer during the inactiveperiods of said intermittent feeding means.

6. A sewing machine for uniting, while arranged face to face, two layersof pile fabric or the like having a frictional backing, comprising awork support; a reciprocating needle; intermittent feeding meansoperative at the stitch point for engaging the back of one layer of thematerial from beneath to intermittently shift it on the work supportrelative to the needle; and auxiliary feeding means including an elementwith a continuous rough-surface for engaging the back of the secondfabric layer from above opposite the intermittent feeding means at thestitch point; and slip drive means for actuating said auxiliary feedingelement to effect synchronous advance of the second layer with the firstduring the active periods of the intermittent fading means, but allowingsaid auxiliary feeding means to remain quiescent in contact with thematerial during the inactive periods of said intermittent feedingsmeans.

I. A sewing machine for uniting, while ar ranged face to face, twolayers of pile fabric or the like having a frictional backing,comprising a work support; a needle operated from above the worksupport; intermittent feeding means operative at the stitch point forengaging the back of one layer from beneath to intermittently shift iton the work support relative to the needle; a presser foot operative tohold the material down on the work support at the stitch point;auxiliary feeding means including a rough surfaced endless belt whichunder-travels the presser foot and engages the back of the other layerfrom above opposite the intermittent feeding means; and slip drive meansfor actuating the belt to effect synchronous advance of the second layerwith the first, but allowing the belt to dwell with the material duringthe idle periods of the intermittent feeding means.

8. A sewing machine for uniting, while arranged face to face, two layersof pile fabric or the like having a frictional backing, comprising awork support; a needle operated from above the work support;intermittent feeding means operative at the stitch point for engagingthe back of one layer from beneath to' intermittently shift it on thework support relative to the needle: a presser foot for holding thematerial down on the work support at the stitch point; auxiliary feedingmeans including an endless rough-surfaced belt for engaging the back ofthe other layer from above at the stitch point opposite the intermittentfeeding means, said belt being confined to traversea longitudinal guidegroove in the bottom surface of the presser foot; and slip drive meansfor actuating the belt to effect synchronous advance of the second layerwith the first, but allowing the belt to dwell with the materlai duringthe idle periods of the intermittent feeding means.

9. A sewing machine for uniting, while arranged face to face, two layersof pile fabric or the like having a frictional backing, comprising awork support with an over-reaching arm; a needle bar with a needleconfined to vertical reciprocation in a head at the free end of saidarm; intermittent feeding means operative at the stitch point forengaging the back of one layer of the material from beneath to.intermittently shift it on the work support relative to the needle; apresser foot for holding the material down on the work support at thestitch point; auxiliary feeding means including an endlessrough-surfaced belt which runs under the presser foot at the stitchpoint and contacts with the back of the second layer opposite theintermittent feeding means, and means defining a circuit for the beltaround the head of the over-reaching arm; and slip drive means foractuating the belt to effect synchronous advance of the second layerwith the first, but allowing the belt to dwell with the material duringthe idle periods of the intermittent feeding means.

10. A sewing machine for uniting, while arranged face to face, twolayers of pile fabric or the like having a frictional backing,comprising a work support with an over-reaching arm; a

which runs under the presser toot at the stitch 10 pointand ensuesthe-other lavertrom above.

opposite the intermittent i'eedin: means, and a series of spaced rollersdefining a circuit for the belt around the head on the over-reachingarm: and slip drive means for actuating the belt to eil'ect synchronousadvance of the second layer with theflrst. butallowlng thebelt todweilwith the material during the idle periods'o! the intermittent feedingmeans.

ARTHUR L. WIIMOTH.

